Method of producing absorbent or resilient felt



Feb. 13, 1934; PLUMSTEAD 1,947,107

METHOD OF PRODUCING ABSORBENT OR RESILIENT FELT Filed Sept. 4, i931Jbazeph E: Humiead,

as I 7 Mi, xwam, 2 4// Patented Feb. 13, 1934 UNITED STATES- METHOD orPRODUCING ABSORBENTQ on nnsmmn'r FELT Joseph E. Plumstead, Wilmington,Del., assignor to The Jessup & Moore Paper 00., Philadelphia, Pa., acorporation of Application September 4, 1931. SerialNo. 561,242

41 Claims. (01'. 92-13) My present invention relates to an improvedmethod of producing kinked, curled, or crimped fibres from finished orprepared cellulosic fibrous pulp material and to theproduction of asheet 6 of material having substantial. bulk and absorbency andresiliency, andto the production of a J felted product havingsubstantial resilience and waterproof qualities.

An object of the invention is the production 10 of the curled or crimpedfibres from finished or prepared pulp without the necessity of using asdrastic treating solutions as have heretofore been used to produce thedesired degree of bulkiness in the felted fibrous sheet.

or expressed in another way, this object is to provide a method capableof producing a sheet having an increased degree of bulkinws orabsorbency, using the usual or ordinary treating solutionv or treatingsolutions of less or equivalent drasticity. In other words, for atreating solution of given drasticity, the method of the presentinvention produces increased bulk and absorbency in the resultant sheetover that produced by methods used heretofore.

crimped fibres by treatment with less'drastic treating solutions and ina limited and controlled time. v I The invention aims to substitute forthe purely chemical curling treatment, acombination of controlled orlimited mechanical treatment with' a less drastic chemical treatment.

Another object of the invention is rendering the fibres more susceptibleto -curling by mechan- 35109.1 gelatinization of the fibres. or in otherwords,

producing a reactive gel on the surface of the fibres by means of amechanical gelatinizing agent prior to or as a concomitant of thetreatment with thecurling agent, which gel is of 40 increased reactivityor susceptibility to the action of the curling agent.

The invention also aims to increase the susceptibility of the fibres tothe curling agent by mechanical treatment producing partial bruising ofthe individual fibres.

Another object .is to produce curled and crimpedor kinked fibres whichresult ma puffed, swollen and springy or spongy eflect 'in the resultingfelted material into which the curled fibre is formed, producing bulkand'absorbency therein with minimum weight without .need of emphasis onthe securing of maximum reaction of chemical upon the entire surface ofthe fibre. Another object is to provide treating solutions byutilization of certain chemicals for the pro- The invention aims toproduce curled orduction of curling, kinking 'or crimping of preparedfibres.

Another object is to produce the less drastic treating solutions byutilization of spent or partially spent saponaceous liquors eitherfortified or unfortified by fresh reactive chemicals, or by preparingfresh solutions of weaker or less drastic chemicals.

Another object is to produce the less drastic treating solutions byusing less drastic chemicals as or by using a less concentrated solutionof the same or an equally drastic chemical as that used in the usualtreating solution, or by using combinations of two or more chemicals.

Another object is the production of a felted product of substantialabsorbency and resiliency.

A-further object is to provide a product which has a marked afiinity forwaterproofing agents.

Another object is the production of a resilient waterproof relativelynon-absorbentfelted. prod- 16 not.

Other objects will be apparent from the accompanying disclosure. v

The drawing shows diagrammatically and for purposes of illustration,without regard to actual dimensions, a fibre in 1 between balls of aball mill, and in Fig.2 approximately the kinked, curled or crimpedcondition of the fibre after bruising at one or more points and treatedwith the treating solution. No attempt at actual relas5 tive sizebetween the balls and the fibre has been madein the drawing.

Fig. 3 represents diagrammatically a ball mill or equivalent fibrebruising apparatus, in which 3A indicates horizontal ribs or bars forelevating 90 the balls 3E and dropping them in the rotation of thecylinder 3 by suitable drive means as 3F.

Inlet and outlet are indicated at 3C and 3D.

The invention involves treating finished or prepared cellulosic fibreswith treating solutions less drastic or powerful than the usual causticlye treating solution, whether less drastic because of increasedpercentage of diluting solvent or because of the use of a less active ormore inert chemical, and supplementing the treatment to accelerate thecurling or crimping action of the fibres by subjecting the fibres tc'tabruising action for a length of time and in an apparatus such as willonly partially'bruise the length of the individual fibres. The partialbruising at one or more points along the individual fibre length is accomplished according to the present invention by v regulating andcontrolling the time of subjection of the fibres to the bruising action.This provides vulnerable points by the bruised portions, causingselective, localized, or focal reactivity of the physico-chemicallyreactive treating solution, whereby the individual fibre throughout itslength is dififerentially affected and will bend,

and localized gelatinization for the production of pufied pulp but also,if continued, will produce a general gelatinization which will make thewhole fibre more reactive and will also, in a measure commensurate withthe degree to which it is carried, replace the ordinary paper millhydration and gelatinization equipment, namely, heaters, Jordans orother type of hydrating equipment.

The invention therefore also involves the subjection of the fibres tomechanical treatment producing such gelatinization of the surface of thefibres as to form a reactive gel thereon particularly responsive to thecurling agent to accelerate the curling of the fibres.

The treatment of the finished cellulosic fibres with the less drastictreating solution is carried out preferably at the same time with themechanical action to which the fibres are subjected, although it isdesired to not limit the invention to this as the treating andmechanical action may be carried out successively, if desired.

Any suitable means may be employed for carrying out the bruising action,preferably a means capable of thoroughly mixing the treating solutionwith the fibres during the bruising treatment and capable of applying alocalized bruise or abrasion of the fibre.

I have found thatthe bruising action is eflectively accomplished bymeans of balls in a rotary mill provided with means for carrying theballs upwardly and dumping them upon the mass of fibre and treatingsolution and other balls in the bottom of the mill.

The ball mill or other bruising apparatus thus requires a certainirregularity of interior construction providing for carrying thebruising media upwardly and then dumping it against the mass, in orderto produce best results in effecting the bruising action, selectivetreatment, and accelerated curling, according to my present invention.

Partial bruising, mimng, and treating with less powerful or less drasticor other treating solution is preferably all carried out in the ballmill to produce the mnking of the fibres.

The treating solution which may be less drastic than the usual causticlye treating solution may include any of the following chemicals: sodiumhydroxide, sodium sulfide, sodium sulfate, sodium sulfite, sodiumcarbonate, sodium chloride, sodium phosphate, sodium nitrate, aluminumsalts, ammonium hydrate, calcium chloride, calcium hydrate, and soaps,such as spent or par-,

tially spent saponaceous liquors, which saponaceous liquors are eitherfortified or unfortified by fresh reactive chemicals such as caustic lyeand sodium sulfide.

Zinc chloride or other zinc salts. Cupro-ammonium compounds (e. g. amixture usual caustic lye treating solutions (of about memo? of ammoniumhydroxide and a copper salt) or other copper salts or copper compounds.

A solution of caustic lye (of about 2% to 18% concentration) which isless powerful than the 7%-24% concentration) may be used and willproduce the desired effect upon the partially bruised fibre, thebruised'portions of the cellulose fibre being more reactive than theother portions. This solution will also be effective where themechanical treatment is such as to provide a reactive gel surface on theentire body of the fibre.

The present invention therefore enables the use of weaker caustic lyesolutions or other treating solutions of reduced power to accomplish thesame bulk and absorbency of the felted sheet as is produced by purelyphysico-chemically kinked, curled, and crimped fibre. This is due to theincreased sensitivity to treating solution of the portions of the fibreaffected by the mechanical bruising action, to cause an increased orextra kinking, curling, or crimping of the fibre. This produced bulk andpufiiness of the felted sheet.

The less drastic treating solution of reduced power, may, of course,still be efiective enough to 100 tend to cause some slight kinking,curling, and

crimping along the whole length of the fibre.

The present invention aims to accelerate the kinking, crimping andcurling effect by the partial bruising causing localized or focalreaction of a treating solution.

If the ball mill treatment were prolonged the progress of the physicalcondition would be marked as follows:-

Step (1). Focal bruising and focal gelatinization.

Step (2). Surface gelatinization extending along the entire fibresurface.

Step (3). An extension of gelatinization into the interior of thefibres.

Step (4). A mass gelatinization in which the fibres begin to lose theiridentity and form into a syrupy gelatinous homogeneous mass.

Of course for a continuous process no definite line can be drawn as towhere one step leaves off and the other begins. It may be definitelystated however that the accelerated curling due to mechanicalgelatinization stops with step two and beyond that point the curlingaction of the treating agent begins to be nullified by additionalmechanical treatment. The present invention involves steps (1) and (2).

Therefore the regulation and control of the time element in the bruisingapparatus or ball mill treatment is highly important in the productionof a kinked, curled, and crimped fibre product resulting in a feltingmachine product of substantial bulk and absorbency.

Expressed in another way, the invention in one aspect involves asubstitution of a mechanical means and less drastic treating solutionfor obtaining a given bulk and absorbency in the felting machine productby focal acceleration of the curling, crimping and kinking effect, inplace of the more powerful physico-chemical treatment. 14 The morepowerful physico-chemical treatment results in a product in which theindividual fibres are affected throughout the length and body thereof tocurl, crimp, and kink the same, with out the assistance of the bruisingtreatment.

A less drastic treating solution for producing a given type of productis used in the ball mill partial bruising treatment according to thepresent invention.

I am taking a finished pulp which may have 150 been originally producedfrom wood or, other vegetable sources according many of the knownmethods, and I am further treating it in .a new way toproduce a newproduct,a felting machine product having bulk and absorbency butcomprising constituent individual fibres crimped or It is ratherdifilcult to place fixed limits on a product, the inherentcharacteristics of which are controlled by the physico-chemical degreesof treatment. In this particular case the physicochemical variables maybe as follows:-- I

(1.) The chemical constituents of the treating solution.

. (2.) The relative percentages of these chemical constituents to eachother. (3.) Percentage of total solids in the treating solution. a

(4.) The duration of the physico-chemical treatment.

(5.) The intensity of the bruising as controlled bythe size of theballs, distance of fall of same and consistency or density of mix.

(6.) Temperature at which treatment is carried out.

The product which I have produced might be described as a fibrous masswhich due to its extreme freeness is incapable of being testedsatisfactorily bythe standard Schopper Riegler freeness tester andrequires a modified Schopper tester as described in volume XCI-No. 9 ofthe Paper Trade Journal, August 28th, 1930, written by Robert M. Boehm,using a bottom orifice of 9/ 64? opening. with the extremes of my methodof treatment, using five liters of mixture and 25 grams of bone drypulp, the bottom readings will be from 350 to 710 c. c.

In case the mechanical treatment in the ball mill is continued to adegree of gelatinization and for the purpose of doing work ordinarilyleft for the beater and Jordan, the figure of1'l10 c. c. might becarried on up even to complete gelatinization. However, if the durationof the ball mill treatment is limited to not over one-half an hour thewashed fibre will show within the test range as outlined above.

I am producing a certain type of product in any. case, although thismethod may permit me to carry the mechanical treatment to a point,whicli. is-.l..ordinarily accomplished ,only in the .papermill by meansof heaters and Jordans or by means of some other-type of hydrating ma-In comma alpractice we will always be making clefi nite grades orqualities of product and we will'therefore in commercial practice alwaysbe comparing the concentrations required to produce'a given drasticityof treating solution which may be used to produce the grade of productwhich we may have under consideration. Thewater only, without any ballmill treatment. The second sample was treated with water only using,

ball mill treatment and shows the slowing effect of the ball milltreatment with no reactive chemical present. The third and fourth itemsshow the freeing effect of the ball mill in the presence of a reactivechemical, for the 10 minute and 20 minute periods of time. Thegelatinization in the 20 minute experiment of the third exampleindicates-more curling taking place than in the 10 minute experimentusing the'same strength of treating chemical.

Treating solu- Bottom Duration oi Mechanical tion (concenoutletfreetreatment nation) method new 1 10 minutes.. Water Agitation..- 638c. c. 2 10minutes W for Ballmill .c. 3 20minutes-. .c. 4 10 minutesc. 510minutes-...{ N .c. 6 l0 minuies- 10% NaOH Ball mill 450 c. c. 7 10minutes 10% Na Ball mill 575 c. c. 8 15 minutes- 5% NaOH..- Ball mill600 c. c. 9 10 minutes 21% NaOH Ball mill 412 c. c. 10 10 mmutes-. mN81s-- all mill 420 c. c. g :3 rmniigugnu 2g, gazgfiun Ball mill 710 c.c.

u a I NB }Bali 111111 565 c. c. 13 10minutes.--. ff fl g- }Bal1mili4817c. c.

- east-"- 14 10 minutes 14 oNalco-i: }Ballmill 625 c. c.

It is to be noted that the kraft pulp tested in this particular casewithout the use of any caustic at all has a freeness of only 718 whereasand used in the mechanical treatment in the. ball producing curling orcrimping of finished pulp is regarded as novel.

Reference is made to my copending application Ser. NO. 558,185, Aug. 19,1931 for Method of producing absorbent or resilient felt which concernssodium sulfide fibre curling treatment.

Reference is also made to my copending application Ser. No. 558,826,filed Aug. 22, 1931 for Method of producing absorbent or resilient feltin which a fibre curling treatment is disclosed involving the use ofsome of the chemicals herein 30 referred to.

My invention involves recognition of the fact that when a cellulosicfibre is bruised at a particular point, the bruised portion of theindividual .will nullify .these "physical characteristics obtained byarelatively short treatment. The balls must be carried well up inrotation in the bruising ball mill, so'that the maximum fall will beobtained and a clear cut bruise will be effected.

A rod mill isless effective than a ball mill, as it may over-bruise someof the fibres. Also a hammer mill of some sort-might be used as thebruising apparatus.

It will be apparent that my invention is not confined to a definitemechanical device, nor to simultaneous treatment .or impregnation withchemical and bruising. The fibres may be saturated with the treatingsolution and bruised in a ball mill or a shredder after saturation orthey may be bruised in water suspension and this water displaced by thetreating chemical, a

, mechanical bruising treatment.

It will be understood that where, in the specification and claims,bruising and treating the fibres is referred to, this is to bebroadlyconstrued to include simultaneous bruising and treating, or firstbruising and then treating, or first treating and then bruising. It isapparent that in the latter case the accentuated treatment ordifierential reactivity cannot take place until after the saturatedfibre is bruised.

The length of time required is dependent upon the size of the mill orbruising apparatus and the rate of feed of the material.

In a small batch mill, from 8 to 15 minutes has been required to producethe desired partial bruising effect, using balls as the bruising media.As a maximum permissible time for the bruising treatmentapproximatelyone-half hour N is may be stated, it being understood that this can onlybe roughly determined in view of the other factors to be considered,such as the size of the mill and the rate of feed.

The quality of the resulting product will be varied by varying theduration of treatment, the temperature, and the strength and reactivityof the treating solution.

With a 1 inch steel ball and a dropof approximately 14 inches, and apulp suspension of 6% density, 15 minutes produce a generallysatisfactory product. This suspension may be passed through a pipe, itis semi-fluid and thick, but not non-fluid. My copending application361,708 filed May 9, 1929, issued as Patent No. 1,830,131 dated Nov. 3,1931, deals with a nonfluid suspension.

It will be evident that the bruising step is one of degree. If the ballsfall too great a distance they will out instead of bruise the fibre. Athree foot diameter mill will have an effective fall of about two feetand will give good results on stock of 6% consistency when using 1%" to2" balls. The denser the consistency of the stock the greater will bethe fall required and the larger will be the diameter of the ballsrequired. The extremes of diameters should fall within the limits ofinch to 6 inches, the drop from 12 to 120 inches, and the consistencyfrom 1% to 10%.

Additional degree of bruising might go so far as to cause a cutting ofthe fibres, an efi'ect not ordinarily to be desired. Care should betaken to prevent this in producing the product described. This cuttingof the fibres might be caused by the balls being too heavy or fallingfrom too great a distance. In other words, the size of ball and distanceof drop is a function of the density of the mix and both of thesevariables should be worked out to eiiectively bruise the fibre and aretherefore a function of the curling as the fibre curls more at thebruised points. The solution strength however bears more relation to thedegree of curling than does the bruising. In practice the bruising wouldbe developed to the most effective point for a particular grade and thesolution strength for the parinaaior ticular grade desired would bedetermined byexperiment. I

The ball mill or other bruising means if carefully controlled, givestangible assistance in curling the fibre, although if continued for anygreat period of time will have the opposite effect of restraighteningthe fibres again.

My experiments have been carried out on the following mixtures using aball mill and approximately 6% consistency of chemical solution mix andpulp.

M ia'ture A Approx. Approx.

Analysis of chemical (dry basis) 0 solution 0 solution Owns/L I am fullyaware that solutions approximating the mixturesshown, as well ascaustic-lye by itself, have been used for many years for the purpose ofreacting with-the acid cementaceous inter-cellular materials whichnature has provided to bind together the cellulose fibres of wood andother vegetable substances. 1

It is not the purpose of this invention to perform the preliminary pulpproducing operation of neutralizing and dissolving these cementeceoussubstances but rather to take cellulose fibres which have beenpreviously separated and cleansed by any of the well known chemicalprocesses and to treat these fibres as herein described for the purposeof presenting a product diiferent from that produced by any of the usualpulp producing processes namely, the soda process, the sulfite process,the mono-sulfite process or the sulfate or kraft process. The kraftprocess which has been in use for a considerable period of time,involves undercooking .various woody materials in a so-called sulfateprocess. However, the sulfate process is also used to fully cook woodymaterials, but when so practiced it is not ordinarily called the lrraftprocess.

Microscopic examination indicates that caustic soda solution causes athickening of the fibre wall. In the process of thickening,irregularities of the fibre wall are emphasized or magnified, therebycausing the fibre to twist, curl and crinkle.

In the felting or piling up of these twisted fibres countless spaces ofcapillary function are formed, thereby imparting to thefelted productits commercially valuable characteristics of absorbency, extreme bulk,capability of being impregnated. and resiliency.

' The curled or crimped fibres having marked afilnity for attaching tothemselves precipitated waterproofing agents such as rosin, aluminumhydrate, copper hydrate, zinc hydrate, etc. and when so treated thatthese substances are deposited on the surface of the fibres in insolubleform, a springy, waterproof, relatively non-absorbent product is theresult,--a waterproof product which may be compressed and released manytimes without losing its resiliency.

The ball mill treatment shortens the mechanical treatment necessary inthe paper making or felting operation. The ball millmay not be entirelysuited to the softer grades of material such as may be produced by othermethods, but the'ball mill may be inserted in any type of process'andthe material and treating solution passed around it, if desired, asindicated in my copending application, Ser. No. 558,184, filed Aug. 19,1931, for method of producing absorbent felt.

The balls used in the experiments were partly round cast iron balls .andpartly balls with indentations and known under the trade name ofConcavex, produced by the Allis-Chalmers Corp.

It has not beeneconomicallypossible, heretofore to treat pulp withcaustic lye of over 7% strength of solution.

The diificulty has been in the mechanical handling of the pulp due to aslimy saponaceous resultant material which slows up free drainagethrough any kind of a screen. By treating the pulpin a non-fluid state,i. e. at least 10% of. fibrous material, as described in my application361,708, or in a semi-fluid state, this-particular difiiculty has beenovercome. However, it has been found that when a mix thicker than 15% ofpulp to 85% of caustic solution'is used there is a retarding of thedesired kinking, curling, and crimping action. A mix above this densityrequires .a caustic solution of increased concentration in order tosecure the desired curling effect. when a thinner mix than the abovementioned 10% fibre mix, is used, the economic difiiculties andthe'slime and washing difiiculties are encountered .on account of theslowness with which the caustic lye solution'drains from the pu p- Thinpulp drains more slowly than thick pulp because in a thin suspension notonly do the fibres pack in closely but any materials in suspension suchas hemi-celluloses are floated into position between the fibreinterstices and pack more firmly therein.

The present process overcomes washing dimculties.

By using a weak solution of caustic lye. less than 7% concentration, ora less drastic treating chemical than caustic lye, even inconcentrations greater'than 7%, the difii'culty in washing due 'tosliminess is not encountered, and for this rea-- son'a semi-fluid orslushtreatment can be carried-out economically andwithout unduewashingilifiicult'ies.

Reference is made to my copending application Ser. No. 558,184, filedAug. 19, 1931, for Method of producingabsorbent felt. in which Idisclose a mechanical method for handling fibres treated with solutionsin concentrations greater than 7%. M

A definition of slowness or "freeness" of cellulosic fibres is thedegree of hydration or water holding power" as measured by the rate atwater drains away from a sheet or mass of thefibres. when the fibres areow the water holding power is great with slow drainage, and converselywhen'the fibres are free, the water holding power is slight with rapiddrainage. This increased water holding power or slowness characteristicmay be: (1) From chemical cause.

(2) From mechanical cause.

(3) Resultof chemical or mechanical gelatinization.

(4) Result of chemical or mechanical shortening or straightening offibres, producing dense or non-porous felted product.

(5) Result of chemical or mechanical kinking, curling or crimping offibres. a

(6) Combination of any or all of above.

If there should be complete internal and external gelatinization of theentire length of the individual fibres, by the mechanical andphysicochemical action, the freeness willbe substantially reduced andslowness will be increased. Prolonged mechanical treatment produces thiscomplete gelatinization and consequent slowness.

The present invention avoids this by limited localized treatmentmaintaining .i'reeness at a maximum in the production of a grade ofproduct in which freeness is desired. I

However, itis understood by those skilled in the art of manufacturingabsorbent and saturating papers and various kinds of felts that certaingrades of material require more inherent density of product than others,and as this density is ordinarily produced by a slowing or a partialgelatinization of the fibre mass before forming it into a sheet, I havefound that by controlling the intensity of the mechanical treatmentgiven to my product during the process of. manufacture, that the densityof the final product may be controlled and the required gelatinizationmore quickly attained when the mechanical treatment is carried out inthe presence of the 116 treating chemical, than when the gelatinizationor slowing of the product is carried out mechanically after washing'outthe treating chemical. Therefore, for certain grades I prolong the me-.chanical treatment and obtain a desired curling 13 and slowness in farless total time and with less than half the mechanical equipment than asif the two operations of curling and mechanical slowing orgelatinization were notcarried out simultaneously.

In fact, the invention maybe said to involve the provision of amechanical bruising means for accelerating the phvsico-chemical curlingaction of I the treating agent, by partial bruising of the'fibres in alimited time, thereby rendering the fibres more vulnerable at thebruised points and causing them to twist or curl about those points, orby mechanically gelatinizing or producing a gel on the surface of thefibres, which gel surface is particularly reactive or susceptible to thephysicochemical action of the treating solution, thereby causing theaccelerated curling. 'lhis mechanical gelatinization in the ball millfor a controlled time to produce the reactive gel surface on the fibres,may be performed prior to or as a concomitant of the treating with thecurling agent- In the treatment of cellulose fibres, a purifica-' tionhas been accomplished by the use of caustic or alkalis of less than 7%concentration, but very 5 curling of the fibres with use of less drastictreating solutions at localized bruised points.

' W discovery indicates that the fibre after being bruised is morevulnerable at the bruised point than it is at other points along itslength and that less drastic solutions may be used, whether less drasticbecause of greater percentage of solvent or because of the use of a lessactive or more inert chemical. Other conditions being unchanged, acertain degree of curling may be attained which would not be attainedwere it not for this mechanical focal fibre bruising. The kneaderprocess does not bruise the fibres; it simply rubs one fibre against theother in a dense mass. The ball mill or other mechanical bruisingcontrivance actually hits a blow at a focal point on the fibre at a timewhen the fibre is resting against a substantially non-yielding body.

Any type of equipment which cause the fibre to be bruised between twohard surfaces in the presence of water or a water solution will causethis gelatinization.

Among these difierent types of equipment for producing gelatinization,are the following:-

Ball mills, rod mills, pebble mills, beating engines, Jordan engines,bruising engines, vemical hydrator, attrition mills, hammer mills,roller mills and various types of shredders too numerous to mention.The-ball mill is only one of several devices in which my method ofproducing the mechanical gelatinization may be performed.

I have found that the apparatus and method of conducting and by-passingthe treating solution, disclosed in my copending application 361,708,filed May 9, 1929, may be used to advantage in a sulfate or kraftwood'pulp treatment, using the by-pass arrangement shown therein for thepurpose of producing an absorbent felt. While the kraft liquor is not asdrastic at a given percentage strength of solution as is soda pulpliquor, this is partially or wholly-compensated for by the ball millbruising treatment, described herein. In applying the bypass feature ofapplication 361,708 to the present invention, the treating solution forthe ball mill or other bruising apparatus would be by-passed thereto asto the impregnating hieader shown in 361,708.

Where caustic lye is used as the treating solution, I may remove it orseparate it from the pulp by either pressing, centrifuging or by waterdisplacement.

Caustic lye as herein referred to is of broader scope than caustic sodain that it may be a regenerated alkali and may contain certain otheralkali than caustic soda, such as caustic potash, sodium or potassiumcarbonates, all of which are alkalis having the same general chemicalreactions as caustic soda. It will be understood, however, that wherevercaustic lye is referred to, caustic soda or any equivalent alkali havingthe same general reactions is to be regarded as disclosed in thatconnection.

It is not intended to limit the invention to the specific illustrationsgiven in the specification by way of example, nor to any fixed limits ofsolution concentrations or other factors entering into my method, as itwill be apparent that these may be considerably varied within the'scopeof the invention.

I claim:

1. .The hereindescribed process of accelerating the kinking, curling,and crimping of finished or prepared cellulosic fibres consisting inbruis- I ing the individual fibres at one or more p ints on the lengthof the fibre, and treating the fibres with a physico-chemically reactivetreating solution, thereby causing selective or pronounced reactivity ofthe treating solution at the bruised points, and consequent acceleratedcurling of the fibres.

2. The hereindescribed process of accelerating the kinking, curling, andcrimping of finished or prepared cellulosic fibres consisting in.partially .bruising the individual fibres, and treating the fibres withtreating solution, thereby producing differential reactivity of thetreating solution on the body of each 'of the partially bruised fibres,and consequentaccelerated curling of the fibres.

3. The hereindescribed process of accelerating the kinking, curling, andcrimping of finished cellulosic fibres consisting in subjecting thefibres to a bruising action for a length of time such that theindividual fibres will be only partially bruised along the lengththereof, and treating the fibres with ,a physico-chemically reactivetreating solution, thereby producing difierential reactivity of thetreating solution on the body of each of the partially bruised fibres.

4;. The hereindescribed process of accelerating the kinking, curling,and crimping of finished cellulosic fibres consisting in partiallybruising the individual fibres, and substantially simultaneouslytreating the fibres with treating solution, thereby producingdifferential reaction of the treating solution on the body of each ofthe partially bruised fibres, and consequent accelerated curling of thefibres.

5. The hereindescribed process of accelerating the kinking, curling, andcrimping of finished cellulosic fibres consisting in subjecting thefibres to a bruising action for a length of time such that the fibreswill be only partially bruised along the length thereof, andsubstantially simultaneously treating the fibres with aphysicochemically reactive treating solution, thereby producingdifferential reactivity of the treating solution on the body of each ofthe partially bruised fibres.

. 6. The hereindescribed process of kinking, curling, and crimpingfinished cellulosic fibres ,consisting in partially bruising theindividual fibres, and treating the fibres with treating solution ofsuch reduced drasticity as to aifect but slightly the unbruised portionof the fibres but which will produce pronounced reactivity at thebruised points and consequent curling of the fibres.

7. The process according to claim 3 in which said treating solutionconsists oi caustic lye solution substantially less powerful thancaustic lye 01 a strength which would be required alone, i. e. withoutthe bruising, to produce a. given degree of kinking, curling andcrimping of the fibres as measured by freeness and absorbency.

8. The process of claim 3 in which said bruising action is continued fora length oi time within one-halt hour. v

9. The process of claim 3 including carrying out said bruising action bysubjecting the fibres to the action of balls in a ball mill.

10. The process 01 claim 3 including carrying out said bruising actionby subjecting the fibres to the action" of balls in a ball mill, anddropping kinking the fibres according to claim 1, including inizationand slowing of the pulp mass necessary for the proper felting of thedesired felt product.

12. The method of claim 1 in which said treat-- ing solution is lessdrastic than causticlye treating solution which alone, i. e. without thebruising, would produce the kinking and comprises partially spentsaponaceous liquors.

l3.' The method of claim 1 in which said treating solution is lessdrastic than caustic lye treating solution which would-be required ofitself, 1. e. without the bruising, to produce the desired kinking andcomprises spent or partially spent saponaceous liquors fortified withfresh reactive chemicals such as caustic lye ,or less drastic chemicalsthan caustic lye such as sodium sulfide.

14. 'I'he'method of claim 1' in which said treating solution is lessdrasticthan caustic lye treating solution which would be required ofitself, i. e. without .the bruising, to produce the ,desired kinking andcomprises partially spent saponaceous liquors, and in which saidbruising action is carried out by subjecting the fibres to the action ofthe balls in a ball mill.

15. The method ofclaim l including carrying out the bruising of. thefibres in a water suspen-" sion and subsequently carrying out thephysicochemical treatment of the bruised fibres by displacing the waterby the treating solution.

16. The method of claim 1 including first treat- .ing the fibres bysaturating the fibres with treating solution and subsequently bruisingthe saturated fibres.

17. The process of claim 3 in which said bruising action is continuedfor from 8 to 15 minutes.

18. The process of claim 3 in which said bruising action iscontinued forfrom 8 to 15 minutes and is carried out by subjecting the fibres to theaction of balls in a ball mill, and dropping the balls in the bruisingtreatment onto the fibres through a drop of from 12 to 120 inches.

19. The process of claim 3 in which said bruising action is continuedfor from 8 to 15 minutes and is carried out by subjecting thefibres tothe action of balls in a ball mill. and dropping the balls in thebruising treatment onto the fibres through a drop offrom 12 to 120inches, the pulp suspension containing said fibres being of from ingsolution of the same percentage solution or.

concentration.

22. The process of claim 35 in which said treating solution is lessdrastic than caustic'lye treating solution of about 7% to 24%concentration.

, 23. As a new article of manufacture, a felting machine product havingbulk and absorbency and comprising constituentnifferentially bruised andfocally treated individual fibres, said product havi& a freeness of 350c. c. to 'i10 c. 0. using 5 liters of mixture and 25 grams of bone-drypulp, using ja bottom orifice of 9/64 opening method consisting insubjecting fin- 24. The

fibrous cellulosic pulp to me-.

ished or prepared chanical bruising treatment such as to render thecellulose fibres more reactive or responsive to a curling agent, andtreating the fibres with a curling agent.

25. The method accordingto claim 24 in which said mechanical treatmentis such as to partially bruise the individual fibres at one or morepoints on the body thereof thereby causing focal reactivity of saidcurling agent at the bruised points and consequent accelerated curlingof the fibres.

26. The method according to claim 24 in which said mechanical treatmentis efiected in a ball mill, and controlling the time of treatment insaid ball mill so that the individual fibres are only partially bruisedon the body thereof.

27. The method according to claim 24 in which said mechanical andcurling agent treatments are effected substantially simultaneously.

28. The method according to claim 24 in which said curling agent is ofless drasticity than the curling agent which without the bruising wouldbe required to produce of itself the same degree of curling.

29. The method according to claim 24 in which said mechanical treatmentis such as to produce a reactive gel upon the surface of the fibres,said curling agent acting with accelerated reactivity 1J0 same, saidcurling agent being of less drasticity 2.1;-

than the curling agent which would otherwise be required to produce ofitself the same degree of curling.

31. The hereindescribed process of'acceleratging the kinking,- curling,and. crimping of finished or prepared cellulosic fibres consisting inmechanically gelatiniz'ing the fibres for a sufiicient time to produce agel upon the surfaces of the fibres, said gel being of increasedreactivity to curling agent, and treating said reactive gel surfacedfibres with curling agent.

32. The method of claim 31 in which said curling agent may be of reducedpower or drasticity, as compared with the curling agent which wouldotherwise berequired to produce of itself' the same degree of curling.

33. The method of claim 24 including forming the curled fibres into anabsorbent and resil-, lent felted product.

- 34. The hereindescribed process of kinking,

curling and crimping finished cellulosic fibres consisting in partiallybruising the individual fibres, and treating the fibres with a treatingsolution of such reduced drasticity as would not of itself, 1. e.without the bruising, produce the ,desired kinking butv which willproduce pro-.

nounced reactivity -at the bruisedpoints and consequent curling of thefibres. 35. The hereindescribed process of accelerat- I ing the kinking,curling, and crimping of finished or prepared cellulosic. fibresconsisting in partially bruising the individual fibres, and treating thefibres with treating solution, thereby producing differential reactivityof the treating solution on the body ofeach of the partially bruisedfibres, and consequent accelerated curling of the fibres, said treatingsolutionbeing caustic lye of such reduced drasticity as would not ofitself, 1. e. without the bruising. produce the desired kinlclngbutwhich will produce pro- 150,

nounced reactivity at the bruised points and consequent curling of thefibres.

36. The hereindescribed process of kinking, curling and crimpingfinished cellulosic fibres consisting in partially bruising theindividual fibres, and treating the fibres with a treating solution ofsuch reduced drasticity as would not of itself, i. e. without thebruising, produce the desired kinking but which will produce pronouncedreactivity at the bruised points and consequent curling of the fibres,said treating solution'being a. solution of at least one materialselected from a group consisting of sodium sulfide, sodium carbonate,sodium chloride, sodium sulfate, sodium sulfite, sodium phosphate,sodium nitrate, zinc salts including zinc chloride cuprammoniumcompounds, copper compounds including copper salts, aluminumsaltslammonium hydrate, calcium hydrate, calcium chloride, soaps, spentsaponaceous liquors, and partially spent saponaceous liquors, whichsaponaceous liquors are fortified by fresh reactive alkaline material.

3'7. The hereindescribed process of curling or kinking felting fibreswhich have been prepared by removing cementaceous material therefromconsisting in partially bruising the fibres at a point or at segregatedpoints along their lengths treating the bruised fibres with aphysicochemical solution to produce the kinking and subjecting thefibres to a further bruising action in the presence of physico-chemicalreactive solution to produce gelatinization of the fibres necessary forthe felting of the product.

memoir 38. A process according to claim 37 in which the bruising isperformed by balls in a ball mill.

39. A process according to claim,37 in which the further bruising actionfor gelatinization is performed by the same means which is employed inthe kinking operation.

40. A method according to claim 1 in which the bruised fibres treatedwith the physico-chemical solution are gelatinized with a change in thesuspending liquid.

41. The hereindescribed process of kinking, curling and crimpingfinished cellulosic fibres consisting in partially bruising theindividual fibres, and treating the fibres with a treating solution ofsuch reduced drasticity as would not of itself, i. e. without thebruising, produce the desired kinking but which will produce pronouncedreactivity at the bruised points and consequent curling of the fibres,said treating solution being a solution of at least one materialselected from a group consisting of sodium sulfide, sodium carbonate,sodium chloride, so-

dium sulfate, sodium sulfite, sodium phosphate,-,

sodium nitrate, zinc salts including zinc chloride, cuprammoniumcompounds, copper compounds including copper salts, aluminum salts,ammonium hydrate, calcium hydrate, calcium chloride, soaps, spentsaponaceous liquors, and partially spent saponaceous liquors.

JOSEPH E. PLUMSTEAD.

